120 Psyche [December 
sult was obtained with crickets which had been starved for 
several days and then fed on grains of wheat. The crop contained 
large bits both of the hull and of the starchy endosperm. The 
mesenteron contained several large bits of hull but no pieces of 
endosperm as large as those in the crop (Pl. VU, 2, 3, 4). 
It will be seen from the foregoing that as a g.uting for the exclu- 
sion of large particles from the mesenteron the proventriculus has, 
in the cricket, little or no efficiency, since it allows even fragments 
of quartz to pass through it. Indeed a study of the arrangement 
of the backward directed teeth and the strong muscular coat will 
make it evident that particles caught in the proventriculus will be 
forced towards the mesenteron. The action of the proventriculus 
might be compared with that of the rollers in a mill; anything 
caught between the rollers is carried onward, if it is strong enough 
to resist the breaking power of the rollers it will come out unaltered 
on the other siae, if not it will be crushed. 
In many insects the teeth of the proventriculus are so poorly 
developed that they can have little or no triturating action. In 
others this organ serves some special purpose as in the honey sac 
of the bee (Cheshire), or the combined pump and valve of the house 
fly (Hewitt). In the cricket, however, the structure of the pro- 
ventriculus and the condition of the food after passing through it 
leave no room for doubt that this organ has a definite triturating 
function. 
REFERENCES. 
1. Straus-Durckheim, H. 1828. Considérations générales sur 
Anatomie comparée des Animaux articulés. Pp. 263-265. 
2. Burmeister. 1836. Manual of Entomology (Shuckard’s trans.). 
London. Pp. 408-409. 
3. Plateau, F. 1874. Recherches sur les Phénoménes de la 
Digestion chez les Insectes. Mém. de l’Acad. Roy. des Se. 
des lettres et des Beaux-Arts de Belgique. Bruxelles, XLI. 
Pp. 104-106. 
4. Miall, L. C. and Denny, A. 1886. The Structure and Life 
History of the Cockroach. London. Pp. 117-130, 131. 
5. Emery, C. 1888. Ueber den Sogenannten Kaumagen einiger 
Ameisen. Zeitschr. f. Wissen. Zool. XLVI, 378-412. 
6. Kolbe, H. J. 1893. Ejinfiihrung in d. Kenntniss d. Insekten, 
Berlin. Pp. 576, 590. 
